Reports measurements of air change rates made on approximately 250 dwellings, occupied by low income households in 14 cities, in all major climatic zones of the United States. Two types of measurements were used : a tracer-gas decay technique using air sample bags and a fan depressurization test that measures induced air exchange rates. Shows that for this group of dwellings natural air infiltration rates have an approximate lognormal distribution.
Discusses the use of a tracer to measure the dispersal of air pollutants. Suggest use of Freon-12 or sulphur hexafluoride as tracer. Describes release of tracer, collection of samples in bottles, concentration of sample and analysis in gas chromatograph. Gives results of field trial and concludes that test method is very promising for studying local air movements.
Describes the basis of operation of electron absorption detector and the nature and causes of the erroneous and anomalous responses it may generate. Suggests pulse sampling technique asan alternative method of analysis. This retains the sensitivity of the simple low potential ion chamber method, but is substantially free of errors and anomolous responses. Describes the basis of this improved method and gives an account of the technique for its use in quantitative and qualitative analysis.
Reports tests made on a mobile home to evaluate its thermal performance. Describes home, instrumentation and test procedure. Gives energy consumption as a function of indoor-outdoor temperature difference. Finds that oversized heating plant resulted in low seasonal operating efficiency. Air infiltration was measured using pressurization technique and SF6 as a tracer gas. The latter showed that operation of the heating plant induced higher air infiltration rates. Reports thermographic survey of interior surfaces which showed air paths formed by wrinkles in the surface insulation.
Gives theoretical justification for the use of tracer gas method for measuring air infiltration. Describes automated instrumentation system using sulphur hexafluoride as a tracer gas. The system consists of an electron capture detector, an automation unit, an SF6 storage and injection panel, a cassette recorder and corresponding plumbing and tanks. Gives examples of field use of system.
Describes a system which measures the rate of air infiltration in buildings using sulphur hexafluoride as a tracer gas. Discusses two methods for evaluating the infiltration rate,the decay method and the constant concentration method. The system automatically operates a portable electron capture detector /chromatograph and samples air on a one-minute cycle. In the decay method the slope of concentration vs time on a semilogarithmic plot can be used to compute infiltration rate.
Reviews use of tracer compounds to demonstrate the transfer of pollutants from one local area or city to another. A study of gaseous compounds resulted in the selection of three suitable materials:sulphur hexafluoride, bromotrifluoromethan andOctafluorocyclobutane. These materials are all non-toxic, rare in the atmosphere and can be readily dispersed from tanks.Describes two systems developed to detect tracer gases. Sensitivity of 10-5 p.p.m. was achieved for sulphur hexafluoride without concentration of the sample. Gives method for collectingair samples and analysing them.
Describes use of SF6 in tracer gas studies to determine solvent fumes in indoor and outdoor environments and how meteorological conditions affect SO2 content of atmosphere. Lists instrumentation used. Discusses properties of SF6 and properties required of a tracer gas, calibration and comparison of U.S. and Swedish results. Lists practical problems both general and specific to gas chromatography and factors affecting results. Suggests future development prospects stating advantage that lower concentrations of SF6 are required compared with N2O for examples.
Treats development of generalised model of hourly air infiltration in residences. Describes its testing. Uses tracer gas measurements of infiltration in 9 research residences inColumbus, Ohio, under widely varying weather conditions. Estimates various linear and physical models against 7000 measurements. Measures and correlates weather parameters. Correlation coefficients ranged around 0.9 with an error between 0.1 to 0.36 air changes. presents Fortran algorithm.
Discusses ways of increasing accuracy and thoroughness of energy audits of buildings by use of specialized instruments and improved audit techniques. States air infiltration measurements are key item in audit procedure. Describes 'house doctor' kitwhich with records of past energy usage, knowledge of prevailing weather and a questionnaire are used to establish the energy signature of a house. The kit includes blower door, infrared camera, temperature probes and appliance consumption meter. Describes simple tracer gas method using sulphur hexafluoride collected in sample bottles.
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